Tortoise scratching his shell on surfaces?

[JacquesM]

Hi,
As of the last day my wee tortoise has been scratching his shell on the hard surface of the TV unit? He keeps rubbing the back of his shell up against it. I am a bit confused as to why he could be doing this and any help would be appreciated

Thanks in advance!

 

[lisa127]

They all do it. I'm not sure the reason, but it is normal.

 

[keepergale]

Your little tortoise has a TV unit in its enclosure.... thats so cool.